The disclosure relates to the technical field of rolling rolling stock, in particular metal strip, in particular so-called “tailored blanks”, i.e. rolling stock with a desired thickness profile in the longitudinal direction of the rolling stock. If the rolling stock is metal strip, such metal strip is also termed longitudinally profiled metal strip. The associated process is also known as flexible rolling. For various reasons explained below, flexible rolling is today only employed in the cold rolling sector. The products produced by this method are used, for example, in the automobile industry in order to increase passenger safety while at the same time minimizing the vehicle weight.
Published unexamined German patent application DE10041280A1 discloses a method for the flexible cold rolling of metal strip.
WO 00/13820 discloses a method for producing metal strips using a hot rolling process, wherein the strip thickness continuously changes in the longitudinal direction. This variable thickness is adjusted by means of a variable casting roll gap and cooling of the casting rolls. The disadvantage of this solution is that thickness settings cannot be controlled accurately and easily by means of the casting rolls. Moreover, only particular thickness progressions can be produced, thereby limiting the flexibility of the system.
Today, no production of “tailored blanks” takes place using conventional hot rolling trains, because the minimum hot strip thicknesses achievable generally range from 1.2 to 1.5 millimeters, which is insufficient for tailored blanks which often require minimum thicknesses of 0.6 mm. The required thickness range can therefore only be inadequately covered using conventional hot rolling trains for tailored blanks.